ebiten/internal/graphics/program.go

284 lines
7.4 KiB
Go

// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package graphics
import (
"fmt"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
)
type arrayBufferLayoutPart struct {
name string
unit int // e.g. int16 is 2 [bytes]
num int
normalize bool
}
type arrayBufferLayout struct {
parts []arrayBufferLayoutPart
}
func (a *arrayBufferLayout) newArrayBuffer(c *opengl.Context) opengl.Buffer {
total := 0
for _, p := range a.parts {
total += p.unit * p.num
}
return c.NewBuffer(opengl.ArrayBuffer, total*4*maxQuads, opengl.DynamicDraw)
}
func (a *arrayBufferLayout) enable(c *opengl.Context, program opengl.Program) {
for _, p := range a.parts {
c.EnableVertexAttribArray(program, p.name)
}
total := 0
for _, p := range a.parts {
total += p.unit * p.num
}
offset := 0
for _, p := range a.parts {
b := p.unit * p.num
// TODO: Argument order doesn't match with glVertexAttribPointer: Fix them.
c.VertexAttribPointer(program, p.name, p.normalize, total, b, offset)
offset += b
}
}
func (a *arrayBufferLayout) disable(c *opengl.Context, program opengl.Program) {
// TODO: Disabling should be done in reversed order?
for _, p := range a.parts {
c.DisableVertexAttribArray(program, p.name)
}
}
// unsafe.SizeOf can't be used because unsafe doesn't work with GopherJS.
const (
int16Size = 2
)
var (
theArrayBufferLayout = arrayBufferLayout{
parts: []arrayBufferLayoutPart{
{
name: "vertex",
unit: int16Size,
num: 2,
normalize: false,
},
{
name: "tex_coord",
unit: int16Size,
num: 2,
normalize: true,
},
},
}
)
type openGLState struct {
arrayBuffer opengl.Buffer
indexBufferQuads opengl.Buffer
programTexture opengl.Program
lastProgram opengl.Program
lastProjectionMatrix []float32
lastModelviewMatrix []float32
lastColorMatrix []float32
lastColorMatrixTranslation []float32
}
var (
theOpenGLState openGLState
zeroBuffer opengl.Buffer
zeroProgram opengl.Program
zeroTexture opengl.Texture
)
const (
indicesNum = 1 << 16
maxQuads = indicesNum / 6
)
func Reset(context *opengl.Context) error {
return theOpenGLState.reset(context)
}
func (s *openGLState) reset(context *opengl.Context) error {
if err := context.Reset(); err != nil {
return err
}
s.lastProgram = zeroProgram
s.lastProjectionMatrix = nil
s.lastModelviewMatrix = nil
s.lastColorMatrix = nil
s.lastColorMatrixTranslation = nil
if s.arrayBuffer != zeroBuffer {
context.DeleteBuffer(s.arrayBuffer)
}
if s.indexBufferQuads != zeroBuffer {
context.DeleteBuffer(s.indexBufferQuads)
}
if s.programTexture != zeroProgram {
context.DeleteProgram(s.programTexture)
}
shaderVertexModelviewNative, err := context.NewShader(opengl.VertexShader, shader(context, shaderVertexModelview))
if err != nil {
panic(fmt.Sprintf("graphics: shader compiling error:\n%s", err))
}
defer context.DeleteShader(shaderVertexModelviewNative)
shaderFragmentTextureNative, err := context.NewShader(opengl.FragmentShader, shader(context, shaderFragmentTexture))
if err != nil {
panic(fmt.Sprintf("graphics: shader compiling error:\n%s", err))
}
defer context.DeleteShader(shaderFragmentTextureNative)
s.programTexture, err = context.NewProgram([]opengl.Shader{
shaderVertexModelviewNative,
shaderFragmentTextureNative,
})
if err != nil {
return err
}
s.arrayBuffer = theArrayBufferLayout.newArrayBuffer(context)
indices := make([]uint16, 6*maxQuads)
for i := uint16(0); i < maxQuads; i++ {
indices[6*i+0] = 4*i + 0
indices[6*i+1] = 4*i + 1
indices[6*i+2] = 4*i + 2
indices[6*i+3] = 4*i + 1
indices[6*i+4] = 4*i + 2
indices[6*i+5] = 4*i + 3
}
s.indexBufferQuads = context.NewBuffer(opengl.ElementArrayBuffer, indices, opengl.StaticDraw)
return nil
}
func areSameFloat32Array(a, b []float32) bool {
if len(a) != len(b) {
return false
}
for i := 0; i < len(a); i++ {
if a[i] != b[i] {
return false
}
}
return true
}
type programContext struct {
state *openGLState
program opengl.Program
context *opengl.Context
projectionMatrix []float32
texture opengl.Texture
geoM Matrix
colorM Matrix
}
func (p *programContext) begin() error {
c := p.context
if p.state.lastProgram != p.program {
c.UseProgram(p.program)
if p.state.lastProgram != zeroProgram {
theArrayBufferLayout.disable(c, p.state.lastProgram)
}
theArrayBufferLayout.enable(c, p.program)
p.state.lastProgram = p.state.programTexture
p.state.lastProjectionMatrix = nil
p.state.lastModelviewMatrix = nil
p.state.lastColorMatrix = nil
p.state.lastColorMatrixTranslation = nil
c.BindElementArrayBuffer(p.state.indexBufferQuads)
c.UniformInt(p.program, "texture", 0)
}
if !areSameFloat32Array(p.state.lastProjectionMatrix, p.projectionMatrix) {
c.UniformFloats(p.program, "projection_matrix", p.projectionMatrix)
if p.state.lastProjectionMatrix == nil {
p.state.lastProjectionMatrix = make([]float32, 16)
}
copy(p.state.lastProjectionMatrix, p.projectionMatrix)
}
ma := float32(p.geoM.Element(0, 0))
mb := float32(p.geoM.Element(0, 1))
mc := float32(p.geoM.Element(1, 0))
md := float32(p.geoM.Element(1, 1))
tx := float32(p.geoM.Element(0, 2))
ty := float32(p.geoM.Element(1, 2))
modelviewMatrix := []float32{
ma, mc, 0, 0,
mb, md, 0, 0,
0, 0, 1, 0,
tx, ty, 0, 1,
}
if !areSameFloat32Array(p.state.lastModelviewMatrix, modelviewMatrix) {
c.UniformFloats(p.program, "modelview_matrix", modelviewMatrix)
if p.state.lastModelviewMatrix == nil {
p.state.lastModelviewMatrix = make([]float32, 16)
}
copy(p.state.lastModelviewMatrix, modelviewMatrix)
}
e := [4][5]float32{}
for i := 0; i < 4; i++ {
for j := 0; j < 5; j++ {
e[i][j] = float32(p.colorM.Element(i, j))
}
}
colorMatrix := []float32{
e[0][0], e[1][0], e[2][0], e[3][0],
e[0][1], e[1][1], e[2][1], e[3][1],
e[0][2], e[1][2], e[2][2], e[3][2],
e[0][3], e[1][3], e[2][3], e[3][3],
}
if !areSameFloat32Array(p.state.lastColorMatrix, colorMatrix) {
c.UniformFloats(p.program, "color_matrix", colorMatrix)
if p.state.lastColorMatrix == nil {
p.state.lastColorMatrix = make([]float32, 16)
}
copy(p.state.lastColorMatrix, colorMatrix)
}
colorMatrixTranslation := []float32{
e[0][4], e[1][4], e[2][4], e[3][4],
}
if !areSameFloat32Array(p.state.lastColorMatrixTranslation, colorMatrixTranslation) {
c.UniformFloats(p.program, "color_matrix_translation", colorMatrixTranslation)
if p.state.lastColorMatrixTranslation == nil {
p.state.lastColorMatrixTranslation = make([]float32, 4)
}
copy(p.state.lastColorMatrixTranslation, colorMatrixTranslation)
}
// We don't have to call gl.ActiveTexture here: GL_TEXTURE0 is the default active texture
// See also: https://www.opengl.org/sdk/docs/man2/xhtml/glActiveTexture.xml
if err := c.BindTexture(p.texture); err != nil {
return err
}
return nil
}
func (p *programContext) end() {
}